votes: show votes when hovering over post score.

Make it so you can hover over a post's score to see the list of public
upvotes. Also show the upvote count, the downvote count, and the upvote
ratio.

app/components/post_votes_tooltip_component.rb

@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+# This component represents the tooltip that displays when you hover over a post's score.
+class PostVotesTooltipComponent < ApplicationComponent
+  attr_reader :post, :current_user
+  delegate :upvote_icon, :downvote_icon, to: :helpers
+
+  def initialize(post:, current_user:)
+    super
+    @post = post
+    @current_user = current_user
+  end
+
+  def votes
+    @post.votes.includes(:user).order(id: :desc)
+  end
+
+  def vote_icon(vote)
+    vote.is_positive? ? upvote_icon : downvote_icon
+  end
+
+  def upvote_ratio
+    return nil if votes.length == 0
+    sprintf("(%.1f%%)", 100.0 * votes.select(&:is_positive?).length / votes.length)
+  end
+
+  def voter_name(vote)
+    if policy(vote).can_see_voter?
+      link_to_user(vote.user, classes: "align-middle")
+    else
+      tag.i("hidden", class: "align-middle")
+    end
+  end
+end